I believe any 80 th 96 can be interchanged. LMHtruck.com has the shell and all the guts to go in them as well as Broncograveyard.com. I would look for a wreck someware. It'l be a whole lot cheaper.
It is LMCtruck I would forget a junk yard. Ford designed this part to keep the iron content of the countryside up B) . I have yet to see a good gate in a junk yard since they usually are well rusted out long before the truck gets there. If you get a new one from LMC or Jeff's, take some time to do some rust preventive measures. Atleast coat the entire interior of the gate with a product like POR15, and make sure that the drain holes are open when done. I would also coat the outside of the gate at the bottom where the outside skin wraps back up to meet the inside part.